The present invention relates to a cutting tool for internal and external turning operations. More specifically, the invention relates to a turning tool having a main cutting edge and an auxiliary cutting edge for an internal and external turning in the manner of a peeling operation, whereby the cutting edges cooperate with a chip guiding shoulder. Cutting tools of this type are disclosed in German Pat. No. 2,148,318. The prior art cutting tool has the disadvantage that it is extremely sensitive relative to positioning errors. Even a slight tilting about a vertical axis causes a penetration of the work piece by the auxiliary cutting edge, thereby destroying the work piece or causing the auxiliary cutting edge to be lifted off the surface to be machined, whereby a variation in the chip breaking is caused which in turn results in an unpermissible increase in the roughness of the machined surface. Both deviations from the desired condition have resulted in unsatisfactory surface machining.